Technical drying of raw materials
Softwood boards of thicknesses between 12 mm and 45 mm (final thickness) are first technically dried to a timber moisture value of around 10 ± 2% and then pre-planed.
The boards, which are normally pre-planed and technically dried, are visually or mechanically graded according to strength. Grading criteria over and above those for normal strength grading are taken into account for outer layers at higher surface qualities.
Cutting out of knots and defective areas
Any board sections discovered during grading with strength-reducing or unsightly growth deviations such as large knots, resin pockets and bark pockets will be cut out if necessary, depending on the strength and surface class. Individual boards can be joined to make endless lamellae in principle using a finger-shaped, load-transferring bonded joint (finger joint assembly).
The endless lamellae are planed to a uniform thickness.
Adhesive is applied to the wide lamella sides.
A minimum of three crosswise-arranged glued laminate layers or, if necessary, layers made of other derived timber products are placed over each other.
|Application of pressure
The pressure is applied to manufacturer specifications using vacuuming, hydraulic presses or clamping pressure gluing.
Planing of blank
The resulting cross laminated timber blank then hardens under pressure. After hardening, the blank is then planed and chamfered.
|Factory assembly and other work
Further factory assembly work such as the fitting of steel components is then carried out by the cross laminated timber manufacturer.
The adhesive joints are very thin. The adhesive proportion of the finished product is less than 1%.
An extremely dimensionally stable, crack-minimised dual axis load-bearing solid wood product with high strength and exceptional building physics properties is created by drying, homogenisation and strength grading.
Since individual layers are easily shaped before adhesion, components curved in one level can be manufactured. Curved components result in extremely high costs and are very time-consuming due to their manual production.